While it is true that everyone's hair is different, there are some ways to get softer hair.

#1. CONDITIONER.

This is the biggest and best thing you can do. When washing your hair with shampoo and conditioner, use a dab on your mustache (or beard) and let it sit awhile. Then lightly rinse it out after a couple minutes. If you leave a little bit of conditioner in your mustache, good. It will moisturize the hair and make it even softer.

#2. HARSH ALKALINE SHAMPOO

ie. Baby Shampoo. It will make your hair really soft. The alkaline breaks down the coarseness.

#3. MOISTURIZERS

ie. Hand moisturizers, shea butter, that sort of thing.

#4. BRUSH DAILY

Use a natural bristle brush.

#5. TRIM, DON'T CUT.

Cutting your mustache all at once with a sharp razor will leave sharp points at the ends of the hair. If you trim only little bits at a time with dull scissors it will leave softer points and only effect a small percentage of the hairs as opposed to making the whole mustache sharp again.

#6. HOT AIR

Use a blow dryer after shampooing and conditioning.

#7. PERM

Using a perm solution seems a bit drastic, but it will definitely help.

#8. DIET

Adding linseed oil and flaxseed oil to your diet will also make your hair softer. This goes for the whole body. It also makes your skin softer and a bunch of other health benefits.